Electromagnetic device



Dec. 19, 1922. 1,439,543. H. E. FROST.

ELECTROMAGNETIC DEVICE.

FILED JULY9| 1920.

V/7v 3ITNE$57 Irwsu'roa 917m: E? W Patented Dec. 19, 1922.

UNITED STATES PATENT OFFICE.

HOMER E. FROST, OF CLEVELAND, OHIO, ASSIGNOR TO THE ELECTRIC CONTROLLER& MANUFACTURING COIPANY, OF

CLEVELAND, OHIO, A CORPORATION OF OHIO.

ELECTROMAGNETIC DEVICE.

Application filed July 9,

To all whom it may com-em:

Be it known that I, HOMER E. F Ros'r, a citizen of the United States,residing at Cleveland, in the county of Cuyahoga and State of Ohio, haveinvented new and useful Improvements in Electromagnetic Devices, ofwhich the following is a specification.

My invention relates to electromagnetic devices. I have illustrated itin connection with an electromagnetic switch for alternating current,but it may be applied in other devices.

Electromagnets in alternating current circuits frequently retain anobjectionable amount of magnetism or fail to release their armatureswhen the current which energizes the magnet windings is interrupted.

t is the object of this invention to provide a means whereby suchmagnets will promptly dischar e their magnetismon. release theirarmatureshen the energizing current is cut oil.

The accompanying drawing shows diagrammatically the application of myinvention to an electromagnetic switch.

On the drawing, 1 and 2 designate two supply wires connecting a sourceofalternating current to the terminals 3 and 4 of the switch 5. The blades6 and 7 of the switch connect the supply wire to, or disconnect themfrom, the wires 8 and 9 which are connected to the opposite ends of theoperating coil 10 of the electromagnetic switch S. The winding 10 isprovided with the armature 11, shown in the present instance as a core.The armature is pivoted to the switch arm 12 bythe pin 13, the saidarmbeing pivoted on the pin 14. 15 is the fixed contact of the switch, and16 is the movable contact which is carried by the 1920. Serial No.395,021.

switch arm 12. 17 and 18 are wires leading from the respective contacts-15 and 16 to any suitable translating device.

19 is a resistance connected to the wires 8 and 9 and in parallel withthe winding 10. With the resistance 19 the magnet S will release itsarmature without sticking. In one installation where 900 volts were usedwith the resistance connected in parallel with the winding of anelectromagnetic switch, the armature was released promptly upon theopening of the switch 5; but when the resistance 19 was disconnectedfrom the circuit, the armature stuck at 500 volts or more.

I claim 1. In an electromagnetic device, an alternating currentelectromagnet having a magnetic armature, and a reslstance connected inparallel with the energizing winding of the magnet to prevent thearmature from sticking upon the cessation of the current in the winding.1

2. In an electromagnetic device, an alter- .nating current electromagnethaving an open magnetic circuit and a magnetic armature, and a.resistance connected in parallel with the energizing winding of themagnet to prevent the armature from sticking upon the cessation of thecurrent inthe winding.

3. In an electromagnetic device, an alternating current electromagnethaving a movable magnetic circuit and a magnetic armature, and aresistance connected in parallel with the energizing winding of themagnet to prevent the armature from sticking upon the cessation of thecurrent in the winding.

Signed at Cleveland, Ohio, this 30 day of June, 1920.

HOMER E. FROST.

